Nocturnal may seem short on length but is enjoyable throughout and doesn't seem to overstay its welcome.  The "light your sword on fire" mechanic to reveal puzzle clues and help defeat enemies shrouded in the mist is unique and helps the game flow smoothly.  While it can be a bit annoying to miss some lore collectibles or extra ashes to help you get to that next perk upgrade since you can't backtrack after certain points, it does make for an interesting risk vs. reward scenario: do you want to just press ahead or take the chance against the mist and learn more about the game's lore?